A numerical study of piezocone test in Firoozkooh sandy soil under different drained conditions

The piezocone penetration test is commonly used to measure pore water pressure, identify a soil’s profile and estimate its material properties. Depending on the soil type, ranging from clay to sand, undrained, partially drained, or drained conditions may occur during cone penetration. In silt and sand–clay mixtures, the piezocone penetration is characterized by partially drained conditions, which are often neglected in data interpretation. The effect of drainage on piezocone measurements has been mainly studied experimentally. Numerical analyses are rare because taking into account large soil deformations, soil–water and soil–structure interactions, and nonlinear soil behavior are still challenging tasks. In this paper, using advanced hypoplastic constitutive model and ABAQUS finite element software large deformations and nonlinear behavior of soil during penetration was modeled and behavior of firoozkooh saturated sandy soil in different drainage conditions and relative densities was analyzed. Then, using the obtained results, the range of influence of cone penetration on the surrounding soil and the range of partial drainage conditions for Firoozkooh sandy soil were investigated. It was also shown that drainage condition and density had a significant effect on the affected soil area and the trend of changes in excess pore water pressure.